The present invention relates to an architecture for computer processors and computer networks and, in particular, to an architecture for computer processors and computer networks in a broadband environment. The present invention further relates to a programming model for such an architecture.
The computers and computing devices of current computer networks, e.g., local area networks (LANs) used in office networks and global networks such as the Internet, were designed principally for stand-alone computing. The sharing of data and application programs (xe2x80x9capplicationsxe2x80x9d) over a computer network was not a principal design goal of these computers and computing devices. These computers and computing devices also typically were designed using a wide assortment of different processors made by a variety of different manufacturers, e.g., Motorola, Intel, Texas Instruments, Sony and others. Each of these processors has its own particular instruction set and instruction set architecture (ISA), i.e., its own particular set of assembly language instructions and structure for the principal computational units and memory units for performing these instructions. A programmer is required to understand, therefore, each processor""s instruction set and ISA to write applications for these processors. This heterogeneous combination of computers and computing devices on today""s computer networks complicates the processing and sharing of data and applications. Multiple versions of the same application often are required, moreover, to accommodate this heterogeneous environment.
The types of computers and computing devices connected to global networks, particularly the Internet, are extensive. In addition to personal computers (PCs) and servers, these computing devices include cellular telephones, mobile computers, personal digital assistants (PDAs), set top boxes, digital televisions and many others. The sharing of data and applications among this assortment of computers and computing devices presents substantial problems.
A number of techniques have been employed in an attempt to overcome these problems. These techniques include, among others, sophisticated interfaces and complicated programming techniques. These solutions often require substantial increases in processing power to implement. They also often result in a substantial increase in the time required to process applications and to transmit data over networks.
Data typically are transmitted over the Internet separately from the corresponding applications. This approach avoids the necessity of sending the application with each set of transmitted data corresponding to the application. While this approach minimizes the amount of bandwidth needed, it also often causes frustration among users. The correct application, or the most current application, for the transmitted data may not be available on the client""s computer. This approach also requires the writing of a multiplicity of versions of each application for the multiplicity of different ISAs and instruction sets employed by the processors on the network.
The Java model attempts to solve this problem. This model employs a small application (xe2x80x9cappletxe2x80x9d) complying with a strict security protocol. Applets are sent from a server computer over the network to be run by a client computer (xe2x80x9cclientxe2x80x9d). To avoid having to send different versions of the same applet to clients employing different ISAs, all Java applets are run on a client""s Java virtual machine. The Java virtual machine is software emulating a computer having a Java ISA and Java instruction set. This software, however, runs on the client""s ISA and the client""s instruction set. A version of the Java virtual machine is provided for each different ISA and instruction set of the clients. A multiplicity of different versions of each applet, therefore, is not required. Each client downloads only the correct Java virtual machine for its particular ISA and instruction set to run all Java applets.
Although providing a solution to the problem of having to write different versions of an application for each different ISA and instruction set, the Java processing model requires an additional layer of software on the client""s computer. This additional layer of software significantly degrades a processor""s processing speed. This decrease in speed is particularly significant for real-time, multimedia applications. A downloaded Java applet also may contain viruses, processing malfunctions, etc. These viruses and malfunctions can corrupt a client""s database and cause other damage. Although a security protocol employed in the Java model attempts to overcome this problem by implementing a software xe2x80x9csandbox,xe2x80x9d i.e., a space in the client""s memory beyond which the Java applet cannot write data, this software-driven security model is often insecure in its implementation and requires even more processing.
Real-time, multimedia, network applications are becoming increasingly important. These network applications require extremely fast processing speeds. Many thousands of megabits of data per second may be needed in the future for such applications. The current architecture of networks, and particularly that of the Internet, and the programming model presently embodied in, e.g., the Java model, make reaching such processing speeds extremely difficult.
Therefore, a new computer architecture, a new architecture for computer networks and a new programming model are required. This new architecture and programming model should overcome the problems of sharing data and applications among the various members of a network without imposing added computational burdens. This new computer architecture and programming model also should overcome the security problems inherent in sharing applications and data among the members of a network.
In one aspect, the present invention provides a new architecture for computers, computing devices and computer networks. In another aspect, the present invention provides a new programming model for these computers, computing devices and computer networks.
In accordance with the present invention, all members of a computer network, i.e., all computers and computing devices of the network, are constructed from a common computing module. This common computing module has a consistent structure and preferably employs the same ISA. The members of the network can be, e.g., clients, servers, PCs, mobile computers, game machines, PDAs, set top boxes, appliances, digital televisions and other devices using computer processors. The consistent modular structure enables efficient, high speed processing of applications and data by the network""s members and the rapid transmission of applications and data over the network. This structure also simplifies the building of members of the network of various sizes and processing power and the preparation of applications for processing by these members.
In another aspect, the present invention provides a new programming model for transmitting data and applications over a network and for processing data and applications among the network""s members. This programming model employs a software cell transmitted over the network for processing by any of the network""s members. Each software cell has the same structure and can contain both applications and data. As a result of the high speed processing and transmission speed provided by the modular computer architecture, these cells can be rapidly processed. The code for the applications preferably is based upon the same common instruction set and ISA. Each software cell preferably contains a global identification (global ID) and information describing the amount of computing resources required for the cell""s processing. Since all computing resources have the same basic structure and employ the same ISA, the particular resource performing this processing can be located anywhere on the network and dynamically assigned.
The basic processing module is a processor element (PE). A PE preferably comprises a processing unit (PU), a direct memory access controller (DMAC) and a plurality of attached processing units (APUs). In a preferred embodiment, a PE comprises eight APUs. The PU and the APUs interact with a shared dynamic random access memory (DRAM) preferably having a cross-bar architecture. The PU schedules and orchestrates the processing of data and applications by the APUs. The APUs perform this processing in a parallel and independent manner. The DMAC controls accesses by the PU and the APUs to the data and applications stored in the shared DRAM.
In accordance with this modular structure, the number of PEs employed by a member of the network is based upon the processing power required by that member. For example, a server may employ four PEs, a workstation may employ two PEs and a PDA may employ one PE. The number of APUs of a PE assigned to processing a particular software cell depends upon the complexity and magnitude of the programs and data within the cell.
In a preferred embodiment, a plurality of PEs are associated with a shared DRAM. The DRAM preferably is segregated into a plurality of sections, and each of these sections is segregated into a plurality of memory banks. In a particularly preferred embodiment, the DRAM comprises sixty-four memory banks, and each bank has one megabyte of storage capacity. Each section of the DRAM preferably is controlled by a bank controller, and each DMAC of a PE preferably accesses each bank controller. The DMAC of each PE in this embodiment, therefore, can access any portion of the shared DRAM.
In an other aspect, the present invention provides a synchronized system and method for an APU""s reading of data from, and the writing of data to, the shared DRAM. This system avoids conflicts among the multiple APUs and multiple PEs sharing the DRAM. In accordance with th is system and method, an area of the DRAM is designated for storing a plurality of full-empty bits. Each of these full-empty bits corresponds to a designated area of the DRAM. The synchronized system is integrated into the hardware of the DRAM and, therefore, avoids the computational overhead of a data synchronization scheme implemented in software.
The present invention also implements sandboxes within the DRAM to provide security against the corruption of data for a program being processed by one APU from data for a program being processed by an other APU. Each sandbox defines an area of the shared DRAM beyond which a particular APU, or set of APUs, cannot read or write data.
In another aspect, the present invention provides a system and method for the PUs"" issuance of commands to the APUs to initiate the APUs"" processing of applications and data. These commands, called APU remote procedure calls (ARPCs), enable the PUs to orchestrate and coordinate the APUs"" parallel processing of applications and data without the APUs performing the role of co-processors.
In another aspect, the present invention provides a system and method for establishing a dedicated pipeline structure for the processing of streaming data. In accordance with this system and method, a coordinated group of APUs, and a coordinated group of memory sandboxes associated with these APUs, are established by a PU for the processing of these data. The pipeline""s dedicated APUs and memory sandboxes remain dedicated to the pipeline during periods that the processing of data does not occur. In other words, the dedicated APUs and their associated sandboxes are placed in a reserved state during these periods.
In another aspect, the present invention provides an absolute timer for the processing of tasks. This absolute timer is independent of the frequency of the clocks employed by the APUs for the processing of applications and data. Applications are written based upon the time period for tasks defined by the absolute timer. If the frequency of the clocks employed by the APUs increases because of, e.g., enhancements to the APUs, the time period for a given task as defined by the absolute timer remains the same. This scheme enables the implementation of enhanced processing times by newer versions of the APUs without disabling these newer APUs from processing older applications written for the slower processing times of older APUs.
The present invention also provides an alternative scheme to permit newer APUs having faster processing speeds to process older applications written for the slower processing speeds of older APUs. In this alternative scheme, the particular instructions or microcode employed by the APUs in processing these older applications are analyzed during processing for problems in the coordination of the APUs"" parallel processing created by the enhanced speeds. xe2x80x9cNo operationxe2x80x9d (xe2x80x9cNOOPxe2x80x9d) instructions are inserted into the instructions executed by some of these APUs to maintain the sequential completion of processing by the APUs expected by the program. By inserting these NOOPs into these instructions, the correct timing for the APUs"" execution of all instructions are maintained.
In another aspect, the present invention provides a chip package containing an integrated circuit into which is integrated an optical wave guide.